http://git-wip-us.apache.org/repos/asf/marmotta/blob/df172223/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/DifferenceFunction.java
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diff --git 
a/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/DifferenceFunction.java
 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/DifferenceFunction.java
new file mode 100644
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b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/DifferenceFunction.java
@@ -0,0 +1,153 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.marmotta.kiwi.sparql.geosparql.functions;
+
+import org.apache.marmotta.kiwi.persistence.KiWiDialect;
+import org.apache.marmotta.kiwi.persistence.pgsql.PostgreSQLDialect;
+import org.apache.marmotta.kiwi.sparql.builder.ValueType;
+import org.apache.marmotta.kiwi.sparql.function.NativeFunction;
+import org.apache.marmotta.kiwi.vocabulary.FN_GEOSPARQL;
+import org.openrdf.model.Value;
+import org.openrdf.model.ValueFactory;
+import org.openrdf.query.algebra.evaluation.ValueExprEvaluationException;
+import org.openrdf.query.algebra.evaluation.function.FunctionRegistry;
+
+/**
+ * A SPARQL function for doing a difference of a geometry. Should be 
implemented
+ * directly in the database, as the in-memory implementation is non-functional.
+ * Only support by postgres - POSTGIS
+ * <p/>
+ * The function can be called either as:
+ * <ul>
+ *      <li>geof:difference(?geometryA, ?geometryB) </li>
+ * </ul>
+ * Its necesary enable postgis in your database with the next command "CREATE
+ * EXTENSION postgis;" Note that for performance reasons it might be 
preferrable
+ * to create a geometry index for your database. Please consult your database
+ * documentation on how to do this.
+ *
+ * @author Xavier Sumba ([email protected]))
+ */
+public class DifferenceFunction implements NativeFunction {
+
+    // auto-register for SPARQL environment
+    static {
+        if 
(!FunctionRegistry.getInstance().has(FN_GEOSPARQL.DIFFERENCE.toString())) {
+            FunctionRegistry.getInstance().add(new DifferenceFunction());
+        }
+    }
+
+    @Override
+    public Value evaluate(ValueFactory valueFactory, Value... args) throws 
ValueExprEvaluationException {
+        throw new UnsupportedOperationException("cannot evaluate in-memory, 
needs to be supported by the database");
+    }
+
+    @Override
+    public String getURI() {
+        return FN_GEOSPARQL.DIFFERENCE.toString();
+    }
+
+    /**
+     * Return true if this function has available native support for the given
+     * dialect
+     *
+     * @param dialect
+     * @return
+     */
+    @Override
+    public boolean isSupported(KiWiDialect dialect) {
+        return dialect instanceof PostgreSQLDialect;
+    }
+
+    /**
+     * Return a string representing how this GeoSPARQL function is translated
+     * into SQL ( Postgis Function ) in the given dialect
+     *
+     * @param dialect
+     * @param args
+     * @return
+     */
+    @Override
+    public String getNative(KiWiDialect dialect, String... args) {
+        if (dialect instanceof PostgreSQLDialect) {
+            if (args.length == 2) {
+                String geom1 = args[0];
+                String geom2 = args[1];
+                String SRID_default = "4326";
+                /*
+                 * The following condition is required to read WKT  inserted 
directly into args[0] or args[1] and create a geometries with SRID
+                 * POINT, MULTIPOINT, LINESTRING ... and MULTIPOLYGON 
conditions: 
+                 *   example: geof:difference(?geom1, "POLYGON(( -7 43, -2 43, 
-2 38, -7 38, -7 43))"^^geo:wktLiteral)
+                 * st_AsText condition: It is to use the geometry that is the 
result of another function geosparql.
+                 *   example: geof:difference(?geom1, geof:buffer(?geometry, 
50, units:meter))
+                 */
+                if (args[0].contains("POINT") || 
args[0].contains("MULTIPOINT") || args[0].contains("LINESTRING") || 
args[0].contains("MULTILINESTRING") || args[0].contains("POLYGON") || 
args[0].contains("MULTIPOLYGON") || args[0].contains("ST_AsText")) {
+                    geom1 = String.format("ST_GeomFromText(%s,%s)", args[0], 
SRID_default);
+                }
+                if (args[1].contains("POINT") || 
args[1].contains("MULTIPOINT") || args[1].contains("LINESTRING") || 
args[1].contains("MULTILINESTRING") || args[1].contains("POLYGON") || 
args[1].contains("MULTIPOLYGON") || args[1].contains("ST_AsText")) {
+                    geom2 = String.format("ST_GeomFromText(%s,%s)", args[1], 
SRID_default);
+                }
+                return String.format("ST_AsText(ST_Difference(%s , %s )) ", 
geom1, geom2);
+            }
+        }
+        throw new UnsupportedOperationException("Difference function not 
supported by dialect " + dialect);
+    }
+
+    /**
+     * Get the return type of the function. This is needed for SQL type casting
+     * inside KiWi.
+     *
+     * @return
+     */
+    @Override
+    public ValueType getReturnType() {
+        return ValueType.GEOMETRY;
+    }
+
+    /**
+     * Get the argument type of the function for the arg'th argument (starting
+     * to count at 0). This is needed for SQL type casting inside KiWi.
+     *
+     * @param arg
+     * @return
+     */
+    @Override
+    public ValueType getArgumentType(int arg
+    ) {
+        return ValueType.GEOMETRY;
+    }
+
+    /**
+     * Return the minimum number of arguments this function requires.
+     *
+     * @return
+     */
+    @Override
+    public int getMinArgs() {
+        return 2;
+    }
+
+    /**
+     * Return the maximum number of arguments this function can take
+     *
+     * @return
+     */
+    @Override
+    public int getMaxArgs() {
+        return 2;
+    }
+}

http://git-wip-us.apache.org/repos/asf/marmotta/blob/df172223/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/DistanceFunction.java
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diff --git 
a/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/DistanceFunction.java
 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/DistanceFunction.java
new file mode 100644
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b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/DistanceFunction.java
@@ -0,0 +1,160 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.marmotta.kiwi.sparql.geosparql.functions;
+
+import org.apache.marmotta.kiwi.persistence.KiWiDialect;
+import org.apache.marmotta.kiwi.persistence.pgsql.PostgreSQLDialect;
+import org.apache.marmotta.kiwi.sparql.builder.ValueType;
+import org.apache.marmotta.kiwi.sparql.function.NativeFunction;
+import org.apache.marmotta.kiwi.vocabulary.FN_GEOSPARQL;
+import org.openrdf.model.Value;
+import org.openrdf.model.ValueFactory;
+import org.openrdf.query.algebra.evaluation.ValueExprEvaluationException;
+import org.openrdf.query.algebra.evaluation.function.FunctionRegistry;
+
+/**
+ * Returns the shortest distance in units between any two Points of two
+ * geometries. Should be implemented directly in the database, as the in-memory
+ * implementation is non-functional. Only support by postgres - POSTGIS
+ * <p/>
+ * The function can be called either as:
+ * <ul>
+ *      <li>geof:distance(?geometryA, ?geometryB, units:meter) </li>
+ * </ul>
+ * Its necesary enable postgis in your database with the next command "CREATE
+ * EXTENSION postgis;" Note that for performance reasons it might be 
preferrable
+ * to create a geometry index for your database. Please consult your database
+ * documentation on how to do this.
+ *
+ * @author Xavier Sumba ([email protected]))
+ */
+public class DistanceFunction implements NativeFunction {
+// auto-register for SPARQL environment
+
+    static {
+        if 
(!FunctionRegistry.getInstance().has(FN_GEOSPARQL.DISTANCE.toString())) {
+            FunctionRegistry.getInstance().add(new DistanceFunction());
+        }
+    }
+
+    @Override
+    public Value evaluate(ValueFactory valueFactory, Value... args) throws 
ValueExprEvaluationException {
+        throw new UnsupportedOperationException("cannot evaluate in-memory, 
needs to be supported by the database");
+    }
+
+    @Override
+    public String getURI() {
+        return FN_GEOSPARQL.DISTANCE.toString();
+    }
+
+    /**
+     * Return true if this function has available native support for the given
+     * dialect
+     *
+     * @param dialect
+     * @return
+     */
+    @Override
+    public boolean isSupported(KiWiDialect dialect) {
+        return dialect instanceof PostgreSQLDialect;
+    }
+
+    /**
+     * Return a string representing how this GeoSPARQL function is translated
+     * into SQL ( Postgis Function ) in the given dialect
+     *
+     * @param dialect
+     * @param args
+     * @return
+     */
+    @Override
+    public String getNative(KiWiDialect dialect, String... args) {
+        if (dialect instanceof PostgreSQLDialect) {
+            if (args.length == 3) {
+                String geom1 = args[0];
+                String geom2 = args[1];
+                String SRID_default = "4326";
+                /*
+                 * The following condition is required to read WKT  inserted 
directly into args[0] or args[1] and create a geometries with SRID
+                 * POINT, MULTIPOINT, LINESTRING ... and MULTIPOLYGON 
conditions: 
+                 *   example: geof:distance(?geom1, "POLYGON(( -7 43, -2 43, 
-2 38, -7 38, -7 43))"^^geo:wktLiteral)
+                 * st_AsText condition: It is to use the geometry that is the 
result of another function geosparql.
+                 *   example: geof:distance(?geom1, geof:buffer(?geom2, 50, 
units:meter))
+                 */
+                if (args[0].contains("POINT") || 
args[0].contains("MULTIPOINT") || args[0].contains("LINESTRING") || 
args[0].contains("MULTILINESTRING") || args[0].contains("POLYGON") || 
args[0].contains("MULTIPOLYGON") || args[0].contains("ST_AsText")) {
+                    geom1 = String.format("ST_GeomFromText(%s,%s)", args[0], 
SRID_default);
+                }
+                if (args[1].contains("POINT") || 
args[1].contains("MULTIPOINT") || args[1].contains("LINESTRING") || 
args[1].contains("MULTILINESTRING") || args[1].contains("POLYGON") || 
args[1].contains("MULTIPOLYGON") || args[1].contains("ST_AsText")) {
+                    geom2 = String.format("ST_GeomFromText(%s,%s)", args[1], 
SRID_default);
+                }
+                if (args[2].equalsIgnoreCase("'" + 
FN_GEOSPARQL.meter.toString() + "'") || args[2].equalsIgnoreCase("'" + 
FN_GEOSPARQL.metre.toString() + "'")) {
+                    return String.format("ST_Distance( ST_Transform( %s 
,26986), ST_Transform( %s ,26986))", geom1, geom2);
+                }
+                if (args[2].equalsIgnoreCase("'" + 
FN_GEOSPARQL.degree.toString() + "'")) {
+                    return String.format("ST_Distance(%s, %s)", geom1, geom2);
+                }
+                if (args[2].equalsIgnoreCase("'" + 
FN_GEOSPARQL.radian.toString() + "'")) {
+                    return String.format("RADIANS(ST_Distance(%s, %s))", 
geom1, geom2);
+                }
+            }
+        }
+        throw new UnsupportedOperationException("Distance function not 
supported by dialect " + dialect);
+    }
+
+    /**
+     * Get the return type of the function. This is needed for SQL type casting
+     * inside KiWi.
+     *
+     * @return
+     */
+    @Override
+    public ValueType getReturnType() {
+        return ValueType.DOUBLE;
+    }
+
+    /**
+     * Get the argument type of the function for the arg'th argument (starting
+     * to count at 0). This is needed for SQL type casting inside KiWi.
+     *
+     * @param arg
+     * @return
+     */
+    @Override
+    public ValueType getArgumentType(int arg) {
+        return ValueType.GEOMETRY;
+    }
+
+    /**
+     * Return the minimum number of arguments this function requires.
+     *
+     * @return
+     */
+    @Override
+    public int getMinArgs() {
+        return 3;
+    }
+
+    /**
+     * Return the maximum number of arguments this function can take
+     *
+     * @return
+     */
+    @Override
+    public int getMaxArgs() {
+        return 3;
+    }
+}

http://git-wip-us.apache.org/repos/asf/marmotta/blob/df172223/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhContainsFunction.java
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diff --git 
a/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhContainsFunction.java
 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhContainsFunction.java
new file mode 100644
index 0000000..908ecb3
--- /dev/null
+++ 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhContainsFunction.java
@@ -0,0 +1,152 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.marmotta.kiwi.sparql.geosparql.functions;
+
+import org.apache.marmotta.kiwi.persistence.KiWiDialect;
+import org.apache.marmotta.kiwi.persistence.pgsql.PostgreSQLDialect;
+import org.apache.marmotta.kiwi.sparql.builder.ValueType;
+import org.apache.marmotta.kiwi.sparql.function.NativeFunction;
+import org.apache.marmotta.kiwi.vocabulary.FN_GEOSPARQL;
+import org.openrdf.model.Value;
+import org.openrdf.model.ValueFactory;
+import org.openrdf.query.algebra.evaluation.ValueExprEvaluationException;
+import org.openrdf.query.algebra.evaluation.function.FunctionRegistry;
+
+/**
+ * A SPARQL function for analyze the Contains Relate between two geometries.
+ * Should be implemented directly in the database, as the in-memory
+ * implementation is non-functional. Only support by postgres - POSTGIS
+ * <p/>
+ * The function can be called either as:
+ * <ul>
+ *      <li>geof:ehContains(?geometryA, ?geometryB) </li>
+ * </ul>
+ * Contains Relate is calculated with "DE-9IM Intersection Pattern": defined in
+ * "RCC8 Query Functions Table 6" from "DE-9IM Intersection Pattern" from OGC
+ * GEOSPARQL DOCUMENT (
+ * https://portal.opengeospatial.org/files/?artifact_id=47664 )
+ *
+ * @author Xavier Sumba ([email protected]))
+ */
+public class EhContainsFunction implements NativeFunction {
+
+    // auto-register for SPARQL environment
+    static {
+        if 
(!FunctionRegistry.getInstance().has(FN_GEOSPARQL.EH_CONTAINS.toString())) {
+            FunctionRegistry.getInstance().add(new EhContainsFunction());
+        }
+    }
+
+    @Override
+    public Value evaluate(ValueFactory valueFactory, Value... args) throws 
ValueExprEvaluationException {
+        throw new UnsupportedOperationException("cannot evaluate in-memory, 
needs to be supported by the database");
+    }
+
+    @Override
+    public String getURI() {
+        return FN_GEOSPARQL.EH_CONTAINS.toString();
+    }
+
+    /**
+     * Return true if this function has available native support for the given
+     * dialect
+     *
+     * @param dialect
+     * @return
+     */
+    @Override
+    public boolean isSupported(KiWiDialect dialect) {
+        return dialect instanceof PostgreSQLDialect;
+    }
+
+    /**
+     * Return a string representing how this GeoSPARQL function is translated
+     * into SQL ( Postgis Function ) in the given dialect
+     *
+     * @param dialect
+     * @param args
+     * @return
+     */
+    @Override
+    public String getNative(KiWiDialect dialect, String... args) {
+        if (dialect instanceof PostgreSQLDialect) {
+            if (args.length == 2) {
+                String geom1 = args[0];
+                String geom2 = args[1];
+                String SRID_default = "4326";
+                /*
+                 * The following condition is required to read WKT  inserted 
directly into args[0] or args[1] and create a geometries with SRID
+                 * POINT, MULTIPOINT, LINESTRING ... and MULTIPOLYGON 
conditions: 
+                 *   example: geof:ehContains(?geom1, "POLYGON(( -7 43, -2 43, 
-2 38, -7 38, -7 43))"^^geo:wktLiteral)
+                 * st_AsText condition: It is to use the geometry that is the 
result of another function geosparql.
+                 *   example: geof:ehContains(?geom1, geof:buffer(?geom2, 50, 
units:meter))
+                 */
+                if (args[0].contains("POINT") || 
args[0].contains("MULTIPOINT") || args[0].contains("LINESTRING") || 
args[0].contains("MULTILINESTRING") || args[0].contains("POLYGON") || 
args[0].contains("MULTIPOLYGON") || args[0].contains("ST_AsText")) {
+                    geom1 = String.format("ST_GeomFromText(%s,%s)", args[0], 
SRID_default);
+                }
+                if (args[1].contains("POINT") || 
args[1].contains("MULTIPOINT") || args[1].contains("LINESTRING") || 
args[1].contains("MULTILINESTRING") || args[1].contains("POLYGON") || 
args[1].contains("MULTIPOLYGON") || args[1].contains("ST_AsText")) {
+                    geom2 = String.format("ST_GeomFromText(%s,%s)", args[1], 
SRID_default);
+                }
+                return String.format("ST_Relate(%s, %s, 'T*TFF*FF*')", geom1, 
geom2);
+            }
+        }
+        throw new UnsupportedOperationException("ehContains function not 
supported by dialect " + dialect);
+    }
+
+    /**
+     * Get the return type of the function. This is needed for SQL type casting
+     * inside KiWi.
+     *
+     * @return
+     */
+    @Override
+    public ValueType getReturnType() {
+        return ValueType.BOOL;
+    }
+
+    /**
+     * Get the argument type of the function for the arg'th argument (starting
+     * to count at 0). This is needed for SQL type casting inside KiWi.
+     *
+     * @param arg
+     * @return
+     */
+    @Override
+    public ValueType getArgumentType(int arg) {
+        return ValueType.GEOMETRY;
+    }
+
+    /**
+     * Return the minimum number of arguments this function requires.
+     *
+     * @return
+     */
+    @Override
+    public int getMinArgs() {
+        return 2;
+    }
+
+    /**
+     * Return the maximum number of arguments this function can take
+     *
+     * @return
+     */
+    @Override
+    public int getMaxArgs() {
+        return 2;
+    }
+}

http://git-wip-us.apache.org/repos/asf/marmotta/blob/df172223/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhCoveredByFunction.java
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diff --git 
a/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhCoveredByFunction.java
 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhCoveredByFunction.java
new file mode 100644
index 0000000..b5286d2
--- /dev/null
+++ 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhCoveredByFunction.java
@@ -0,0 +1,152 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.marmotta.kiwi.sparql.geosparql.functions;
+
+import org.apache.marmotta.kiwi.persistence.KiWiDialect;
+import org.apache.marmotta.kiwi.persistence.pgsql.PostgreSQLDialect;
+import org.apache.marmotta.kiwi.sparql.builder.ValueType;
+import org.apache.marmotta.kiwi.sparql.function.NativeFunction;
+import org.apache.marmotta.kiwi.vocabulary.FN_GEOSPARQL;
+import org.openrdf.model.Value;
+import org.openrdf.model.ValueFactory;
+import org.openrdf.query.algebra.evaluation.ValueExprEvaluationException;
+import org.openrdf.query.algebra.evaluation.function.FunctionRegistry;
+
+/**
+ * A SPARQL function for analyze the CoveredBy Relate between two geometries.
+ * Should be implemented directly in the database, as the in-memory
+ * implementation is non-functional. Only support by postgres - POSTGIS
+ * <p/>
+ * The function can be called either as:
+ * <ul>
+ *      <li>geof:ehCoveredBy(?geometryA, ?geometryB) </li>
+ * </ul>
+ * CoveredBy Relate is calculated with "DE-9IM Intersection Pattern": defined 
in
+ * "RCC8 Query Functions Table 7" from "DE-9IM Intersection Pattern" from OGC
+ * GEOSPARQL DOCUMENT (
+ * https://portal.opengeospatial.org/files/?artifact_id=47664 )
+ *
+ * @author Xavier Sumba ([email protected]))
+ */
+public class EhCoveredByFunction implements NativeFunction {
+
+    // auto-register for SPARQL environment
+    static {
+        if 
(!FunctionRegistry.getInstance().has(FN_GEOSPARQL.EH_COVEREDBY.toString())) {
+            FunctionRegistry.getInstance().add(new EhCoveredByFunction());
+        }
+    }
+
+    @Override
+    public Value evaluate(ValueFactory valueFactory, Value... args) throws 
ValueExprEvaluationException {
+        throw new UnsupportedOperationException("cannot evaluate in-memory, 
needs to be supported by the database");
+    }
+
+    @Override
+    public String getURI() {
+        return FN_GEOSPARQL.EH_COVEREDBY.toString();
+    }
+
+    /**
+     * Return true if this function has available native support for the given
+     * dialect
+     *
+     * @param dialect
+     * @return
+     */
+    @Override
+    public boolean isSupported(KiWiDialect dialect) {
+        return dialect instanceof PostgreSQLDialect;
+    }
+
+    /**
+     * Return a string representing how this GeoSPARQL function is translated
+     * into SQL ( Postgis Function ) in the given dialect
+     *
+     * @param dialect
+     * @param args
+     * @return
+     */
+    @Override
+    public String getNative(KiWiDialect dialect, String... args) {
+        if (dialect instanceof PostgreSQLDialect) {
+            if (args.length == 2) {
+                String geom1 = args[0];
+                String geom2 = args[1];
+                String SRID_default = "4326";
+                /*
+                 * The following condition is required to read WKT  inserted 
directly into args[0] or args[1] and create a geometries with SRID
+                 * POINT, MULTIPOINT, LINESTRING ... and MULTIPOLYGON 
conditions: 
+                 *   example: geof:ehCoveredBy(?geom1, "POLYGON(( -7 43, -2 
43, -2 38, -7 38, -7 43))"^^geo:wktLiteral)
+                 * st_AsText condition: It is to use the geometry that is the 
result of another function geosparql.
+                 *   example: geof:ehCoveredBy(?geom1, geof:buffer(?geom2, 50, 
units:meter))
+                 */
+                if (args[0].contains("POINT") || 
args[0].contains("MULTIPOINT") || args[0].contains("LINESTRING") || 
args[0].contains("MULTILINESTRING") || args[0].contains("POLYGON") || 
args[0].contains("MULTIPOLYGON") || args[0].contains("ST_AsText")) {
+                    geom1 = String.format("ST_GeomFromText(%s,%s)", args[0], 
SRID_default);
+                }
+                if (args[1].contains("POINT") || 
args[1].contains("MULTIPOINT") || args[1].contains("LINESTRING") || 
args[1].contains("MULTILINESTRING") || args[1].contains("POLYGON") || 
args[1].contains("MULTIPOLYGON") || args[1].contains("ST_AsText")) {
+                    geom2 = String.format("ST_GeomFromText(%s,%s)", args[1], 
SRID_default);
+                }
+                return String.format("ST_Relate(%s, %s, 'TFF*TFT**')", geom1, 
geom2);
+            }
+        }
+        throw new UnsupportedOperationException("ehCoveredBy function not 
supported by dialect " + dialect);
+    }
+
+    /**
+     * Get the return type of the function. This is needed for SQL type casting
+     * inside KiWi.
+     *
+     * @return
+     */
+    @Override
+    public ValueType getReturnType() {
+        return ValueType.BOOL;
+    }
+
+    /**
+     * Get the argument type of the function for the arg'th argument (starting
+     * to count at 0). This is needed for SQL type casting inside KiWi.
+     *
+     * @param arg
+     * @return
+     */
+    @Override
+    public ValueType getArgumentType(int arg) {
+        return ValueType.GEOMETRY;
+    }
+
+    /**
+     * Return the minimum number of arguments this function requires.
+     *
+     * @return
+     */
+    @Override
+    public int getMinArgs() {
+        return 2;
+    }
+
+    /**
+     * Return the maximum number of arguments this function can take
+     *
+     * @return
+     */
+    @Override
+    public int getMaxArgs() {
+        return 2;
+    }
+}

http://git-wip-us.apache.org/repos/asf/marmotta/blob/df172223/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhCoversFunction.java
----------------------------------------------------------------------
diff --git 
a/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhCoversFunction.java
 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhCoversFunction.java
new file mode 100644
index 0000000..ded7b95
--- /dev/null
+++ 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhCoversFunction.java
@@ -0,0 +1,152 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.marmotta.kiwi.sparql.geosparql.functions;
+
+import org.apache.marmotta.kiwi.persistence.KiWiDialect;
+import org.apache.marmotta.kiwi.persistence.pgsql.PostgreSQLDialect;
+import org.apache.marmotta.kiwi.sparql.builder.ValueType;
+import org.apache.marmotta.kiwi.sparql.function.NativeFunction;
+import org.apache.marmotta.kiwi.vocabulary.FN_GEOSPARQL;
+import org.openrdf.model.Value;
+import org.openrdf.model.ValueFactory;
+import org.openrdf.query.algebra.evaluation.ValueExprEvaluationException;
+import org.openrdf.query.algebra.evaluation.function.FunctionRegistry;
+
+/**
+ * A SPARQL function for analyze the Covers Relate between two geometries.
+ * Should be implemented directly in the database, as the in-memory
+ * implementation is non-functional. Only support by postgres - POSTGIS
+ * <p/>
+ * The function can be called either as:
+ * <ul>
+ *      <li>geof:ehCovers(?geometryA, ?geometryB) </li>
+ * </ul>
+ * Covers Relate is calculated with "DE-9IM Intersection Pattern": defined in
+ * "RCC8 Query Functions Table 6" from "DE-9IM Intersection Pattern" from OGC
+ * GEOSPARQL DOCUMENT (
+ * https://portal.opengeospatial.org/files/?artifact_id=47664 )
+ *
+ * @author Xavier Sumba ([email protected]))
+ */
+public class EhCoversFunction implements NativeFunction {
+
+    // auto-register for SPARQL environment
+    static {
+        if 
(!FunctionRegistry.getInstance().has(FN_GEOSPARQL.EH_COVERS.toString())) {
+            FunctionRegistry.getInstance().add(new EhCoversFunction());
+        }
+    }
+
+    @Override
+    public Value evaluate(ValueFactory valueFactory, Value... args) throws 
ValueExprEvaluationException {
+        throw new UnsupportedOperationException("cannot evaluate in-memory, 
needs to be supported by the database");
+    }
+
+    @Override
+    public String getURI() {
+        return FN_GEOSPARQL.EH_COVERS.toString();
+    }
+
+    /**
+     * Return true if this function has available native support for the given
+     * dialect
+     *
+     * @param dialect
+     * @return
+     */
+    @Override
+    public boolean isSupported(KiWiDialect dialect) {
+        return dialect instanceof PostgreSQLDialect;
+    }
+
+    /**
+     * Return a string representing how this GeoSPARQL function is translated
+     * into SQL ( Postgis Function ) in the given dialect
+     *
+     * @param dialect
+     * @param args
+     * @return
+     */
+    @Override
+    public String getNative(KiWiDialect dialect, String... args) {
+        if (dialect instanceof PostgreSQLDialect) {
+            if (args.length == 2) {
+                String geom1 = args[0];
+                String geom2 = args[1];
+                String SRID_default = "4326";
+                /*
+                 * The following condition is required to read WKT  inserted 
directly into args[0] or args[1] and create a geometries with SRID
+                 * POINT, MULTIPOINT, LINESTRING ... and MULTIPOLYGON 
conditions: 
+                 *   example: geof:ehCovers(?geom1, "POLYGON(( -7 43, -2 43, 
-2 38, -7 38, -7 43))"^^geo:wktLiteral)
+                 * st_AsText condition: It is to use the geometry that is the 
result of another function geosparql.
+                 *   example: geof:ehCovers(?geom1, geof:buffer(?geom2, 50, 
units:meter))
+                 */
+                if (args[0].contains("POINT") || 
args[0].contains("MULTIPOINT") || args[0].contains("LINESTRING") || 
args[0].contains("MULTILINESTRING") || args[0].contains("POLYGON") || 
args[0].contains("MULTIPOLYGON") || args[0].contains("ST_AsText")) {
+                    geom1 = String.format("ST_GeomFromText(%s,%s)", args[0], 
SRID_default);
+                }
+                if (args[1].contains("POINT") || 
args[1].contains("MULTIPOINT") || args[1].contains("LINESTRING") || 
args[1].contains("MULTILINESTRING") || args[1].contains("POLYGON") || 
args[1].contains("MULTIPOLYGON") || args[1].contains("ST_AsText")) {
+                    geom2 = String.format("ST_GeomFromText(%s,%s)", args[1], 
SRID_default);
+                }
+                return String.format("ST_Relate(%s, %s, 'T*TFT*FF*')", geom1, 
geom2);
+            }
+        }
+        throw new UnsupportedOperationException("ehCovers function not 
supported by dialect " + dialect);
+    }
+
+    /**
+     * Get the return type of the function. This is needed for SQL type casting
+     * inside KiWi.
+     *
+     * @return
+     */
+    @Override
+    public ValueType getReturnType() {
+        return ValueType.BOOL;
+    }
+
+    /**
+     * Get the argument type of the function for the arg'th argument (starting
+     * to count at 0). This is needed for SQL type casting inside KiWi.
+     *
+     * @param arg
+     * @return
+     */
+    @Override
+    public ValueType getArgumentType(int arg) {
+        return ValueType.GEOMETRY;
+    }
+
+    /**
+     * Return the minimum number of arguments this function requires.
+     *
+     * @return
+     */
+    @Override
+    public int getMinArgs() {
+        return 2;
+    }
+
+    /**
+     * Return the maximum number of arguments this function can take
+     *
+     * @return
+     */
+    @Override
+    public int getMaxArgs() {
+        return 2;
+    }
+}

http://git-wip-us.apache.org/repos/asf/marmotta/blob/df172223/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhDisjointFunction.java
----------------------------------------------------------------------
diff --git 
a/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhDisjointFunction.java
 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhDisjointFunction.java
new file mode 100644
index 0000000..b88a7fd
--- /dev/null
+++ 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhDisjointFunction.java
@@ -0,0 +1,152 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.marmotta.kiwi.sparql.geosparql.functions;
+
+import org.apache.marmotta.kiwi.persistence.KiWiDialect;
+import org.apache.marmotta.kiwi.persistence.pgsql.PostgreSQLDialect;
+import org.apache.marmotta.kiwi.sparql.builder.ValueType;
+import org.apache.marmotta.kiwi.sparql.function.NativeFunction;
+import org.apache.marmotta.kiwi.vocabulary.FN_GEOSPARQL;
+import org.openrdf.model.Value;
+import org.openrdf.model.ValueFactory;
+import org.openrdf.query.algebra.evaluation.ValueExprEvaluationException;
+import org.openrdf.query.algebra.evaluation.function.FunctionRegistry;
+
+/**
+ * A SPARQL function for analyze the Disjoint between two geometries. Should be
+ * implemented directly in the database, as the in-memory implementation is
+ * non-functional. Only support by postgres - POSTGIS
+ * <p/>
+ * The function can be called either as:
+ * <ul>
+ *      <li>geof:ehDisjoint(?geometryA, ?geometryB) </li>
+ * </ul>
+ * Disjoint is calculated with "DE-9IM Intersection Pattern": defined in "RCC8
+ * Query Functions Table 6" from "DE-9IM Intersection Pattern" from OGC
+ * GEOSPARQL DOCUMENT (
+ * https://portal.opengeospatial.org/files/?artifact_id=47664 )
+ *
+ * @author Xavier Sumba ([email protected]))
+ */
+public class EhDisjointFunction implements NativeFunction {
+
+    // auto-register for SPARQL environment
+    static {
+        if 
(!FunctionRegistry.getInstance().has(FN_GEOSPARQL.EH_DISJOINT.toString())) {
+            FunctionRegistry.getInstance().add(new EhDisjointFunction());
+        }
+    }
+
+    @Override
+    public Value evaluate(ValueFactory valueFactory, Value... args) throws 
ValueExprEvaluationException {
+        throw new UnsupportedOperationException("cannot evaluate in-memory, 
needs to be supported by the database");
+    }
+
+    @Override
+    public String getURI() {
+        return FN_GEOSPARQL.EH_DISJOINT.toString();
+    }
+
+    /**
+     * Return true if this function has available native support for the given
+     * dialect
+     *
+     * @param dialect
+     * @return
+     */
+    @Override
+    public boolean isSupported(KiWiDialect dialect) {
+        return dialect instanceof PostgreSQLDialect;
+    }
+
+    /**
+     * Return a string representing how this GeoSPARQL function is translated
+     * into SQL ( Postgis Function ) in the given dialect
+     *
+     * @param dialect
+     * @param args
+     * @return
+     */
+    @Override
+    public String getNative(KiWiDialect dialect, String... args) {
+        if (dialect instanceof PostgreSQLDialect) {
+            if (args.length == 2) {
+                String geom1 = args[0];
+                String geom2 = args[1];
+                String SRID_default = "4326";
+                /*
+                 * The following condition is required to read WKT  inserted 
directly into args[0] or args[1] and create a geometries with SRID
+                 * POINT, MULTIPOINT, LINESTRING ... and MULTIPOLYGON 
conditions: 
+                 *   example: geof:ehDisjoint(?geom1, "POLYGON(( -7 43, -2 43, 
-2 38, -7 38, -7 43))"^^geo:wktLiteral)
+                 * st_AsText condition: It is to use the geometry that is the 
result of another function geosparql.
+                 *   example: geof:ehDisjoint(?geom1, geof:buffer(?geom2, 50, 
units:meter))
+                 */
+                if (args[0].contains("POINT") || 
args[0].contains("MULTIPOINT") || args[0].contains("LINESTRING") || 
args[0].contains("MULTILINESTRING") || args[0].contains("POLYGON") || 
args[0].contains("MULTIPOLYGON") || args[0].contains("ST_AsText")) {
+                    geom1 = String.format("ST_GeomFromText(%s,%s)", args[0], 
SRID_default);
+                }
+                if (args[1].contains("POINT") || 
args[1].contains("MULTIPOINT") || args[1].contains("LINESTRING") || 
args[1].contains("MULTILINESTRING") || args[1].contains("POLYGON") || 
args[1].contains("MULTIPOLYGON") || args[1].contains("ST_AsText")) {
+                    geom2 = String.format("ST_GeomFromText(%s,%s)", args[1], 
SRID_default);
+                }
+                return String.format("ST_Relate(%s, %s, 'FF*FF****')", geom1, 
geom2);
+            }
+        }
+        throw new UnsupportedOperationException("ehDisjoint function not 
supported by dialect " + dialect);
+    }
+
+    /**
+     * Get the return type of the function. This is needed for SQL type casting
+     * inside KiWi.
+     *
+     * @return
+     */
+    @Override
+    public ValueType getReturnType() {
+        return ValueType.BOOL;
+    }
+
+    /**
+     * Get the argument type of the function for the arg'th argument (starting
+     * to count at 0). This is needed for SQL type casting inside KiWi.
+     *
+     * @param arg
+     * @return
+     */
+    @Override
+    public ValueType getArgumentType(int arg) {
+        return ValueType.GEOMETRY;
+    }
+
+    /**
+     * Return the minimum number of arguments this function requires.
+     *
+     * @return
+     */
+    @Override
+    public int getMinArgs() {
+        return 2;
+    }
+
+    /**
+     * Return the maximum number of arguments this function can take
+     *
+     * @return
+     */
+    @Override
+    public int getMaxArgs() {
+        return 2;
+    }
+}

http://git-wip-us.apache.org/repos/asf/marmotta/blob/df172223/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhEqualsFunction.java
----------------------------------------------------------------------
diff --git 
a/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhEqualsFunction.java
 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhEqualsFunction.java
new file mode 100644
index 0000000..0dfa466
--- /dev/null
+++ 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhEqualsFunction.java
@@ -0,0 +1,152 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.marmotta.kiwi.sparql.geosparql.functions;
+
+import org.apache.marmotta.kiwi.persistence.KiWiDialect;
+import org.apache.marmotta.kiwi.persistence.pgsql.PostgreSQLDialect;
+import org.apache.marmotta.kiwi.sparql.builder.ValueType;
+import org.apache.marmotta.kiwi.sparql.function.NativeFunction;
+import org.apache.marmotta.kiwi.vocabulary.FN_GEOSPARQL;
+import org.openrdf.model.Value;
+import org.openrdf.model.ValueFactory;
+import org.openrdf.query.algebra.evaluation.ValueExprEvaluationException;
+import org.openrdf.query.algebra.evaluation.function.FunctionRegistry;
+
+/**
+ * A SPARQL function for analyze the EhEquals between two geometries. Should be
+ * implemented directly in the database, as the in-memory implementation is
+ * non-functional. Only support by postgres - POSTGIS
+ * <p/>
+ * The function can be called either as:
+ * <ul>
+ *      <li>geof:ehEquals(?geometryA, ?geometryB) </li>
+ * </ul>
+ * EhEquals is calculated with "DE-9IM Intersection Pattern": defined in "RCC8
+ * Query Functions Table 6" from "DE-9IM Intersection Pattern" from OGC
+ * GEOSPARQL DOCUMENT (
+ * https://portal.opengeospatial.org/files/?artifact_id=47664 )
+ *
+ * @author Xavier Sumba ([email protected]))
+ */
+public class EhEqualsFunction implements NativeFunction {
+
+    // auto-register for SPARQL environment
+    static {
+        if 
(!FunctionRegistry.getInstance().has(FN_GEOSPARQL.EH_EQUALS.toString())) {
+            FunctionRegistry.getInstance().add(new EhEqualsFunction());
+        }
+    }
+
+    @Override
+    public Value evaluate(ValueFactory valueFactory, Value... args) throws 
ValueExprEvaluationException {
+        throw new UnsupportedOperationException("cannot evaluate in-memory, 
needs to be supported by the database");
+    }
+
+    @Override
+    public String getURI() {
+        return FN_GEOSPARQL.EH_EQUALS.toString();
+    }
+
+    /**
+     * Return true if this function has available native support for the given
+     * dialect
+     *
+     * @param dialect
+     * @return
+     */
+    @Override
+    public boolean isSupported(KiWiDialect dialect) {
+        return dialect instanceof PostgreSQLDialect;
+    }
+
+    /**
+     * Return a string representing how this GeoSPARQL function is translated
+     * into SQL ( Postgis Function ) in the given dialect
+     *
+     * @param dialect
+     * @param args
+     * @return
+     */
+    @Override
+    public String getNative(KiWiDialect dialect, String... args) {
+        if (dialect instanceof PostgreSQLDialect) {
+            if (args.length == 2) {
+                String geom1 = args[0];
+                String geom2 = args[1];
+                String SRID_default = "4326";
+                /*
+                 * The following condition is required to read WKT  inserted 
directly into args[0] or args[1] and create a geometries with SRID
+                 * POINT, MULTIPOINT, LINESTRING ... and MULTIPOLYGON 
conditions: 
+                 *   example: geof:ehEquals(?geom1, "POLYGON(( -7 43, -2 43, 
-2 38, -7 38, -7 43))"^^geo:wktLiteral)
+                 * st_AsText condition: It is to use the geometry that is the 
result of another function geosparql.
+                 *   example: geof:ehEquals(?geom1, geof:buffer(?geom2, 50, 
units:meter))
+                 */
+                if (args[0].contains("POINT") || 
args[0].contains("MULTIPOINT") || args[0].contains("LINESTRING") || 
args[0].contains("MULTILINESTRING") || args[0].contains("POLYGON") || 
args[0].contains("MULTIPOLYGON") || args[0].contains("ST_AsText")) {
+                    geom1 = String.format("ST_GeomFromText(%s,%s)", args[0], 
SRID_default);
+                }
+                if (args[1].contains("POINT") || 
args[1].contains("MULTIPOINT") || args[1].contains("LINESTRING") || 
args[1].contains("MULTILINESTRING") || args[1].contains("POLYGON") || 
args[1].contains("MULTIPOLYGON") || args[1].contains("ST_AsText")) {
+                    geom2 = String.format("ST_GeomFromText(%s,%s)", args[1], 
SRID_default);
+                }
+                return String.format("ST_Relate(%s, %s, 'TFFFTFFFT')", geom1, 
geom2);
+            }
+        }
+        throw new UnsupportedOperationException("ehEquals function not 
supported by dialect " + dialect);
+    }
+
+    /**
+     * Get the return type of the function. This is needed for SQL type casting
+     * inside KiWi.
+     *
+     * @return
+     */
+    @Override
+    public ValueType getReturnType() {
+        return ValueType.BOOL;
+    }
+
+    /**
+     * Get the argument type of the function for the arg'th argument (starting
+     * to count at 0). This is needed for SQL type casting inside KiWi.
+     *
+     * @param arg
+     * @return
+     */
+    @Override
+    public ValueType getArgumentType(int arg) {
+        return ValueType.GEOMETRY;
+    }
+
+    /**
+     * Return the minimum number of arguments this function requires.
+     *
+     * @return
+     */
+    @Override
+    public int getMinArgs() {
+        return 2;
+    }
+
+    /**
+     * Return the maximum number of arguments this function can take
+     *
+     * @return
+     */
+    @Override
+    public int getMaxArgs() {
+        return 2;
+    }
+}

http://git-wip-us.apache.org/repos/asf/marmotta/blob/df172223/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhInsideFunction.java
----------------------------------------------------------------------
diff --git 
a/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhInsideFunction.java
 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhInsideFunction.java
new file mode 100644
index 0000000..b3845bd
--- /dev/null
+++ 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhInsideFunction.java
@@ -0,0 +1,152 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.marmotta.kiwi.sparql.geosparql.functions;
+
+import org.apache.marmotta.kiwi.persistence.KiWiDialect;
+import org.apache.marmotta.kiwi.persistence.pgsql.PostgreSQLDialect;
+import org.apache.marmotta.kiwi.sparql.builder.ValueType;
+import org.apache.marmotta.kiwi.sparql.function.NativeFunction;
+import org.apache.marmotta.kiwi.vocabulary.FN_GEOSPARQL;
+import org.openrdf.model.Value;
+import org.openrdf.model.ValueFactory;
+import org.openrdf.query.algebra.evaluation.ValueExprEvaluationException;
+import org.openrdf.query.algebra.evaluation.function.FunctionRegistry;
+
+/**
+ * A SPARQL function for analyze the Inside Relate between two geometries.
+ * Should be implemented directly in the database, as the in-memory
+ * implementation is non-functional. Only support by postgres - POSTGIS
+ * <p/>
+ * The function can be called either as:
+ * <ul>
+ *      <li>geof:ehInside(?geometryA, ?geometryB) </li>
+ * </ul>
+ * Inside Relate is calculated with "DE-9IM Intersection Pattern": defined in
+ * "RCC8 Query Functions Table 6" from "DE-9IM Intersection Pattern" from OGC
+ * GEOSPARQL DOCUMENT (
+ * https://portal.opengeospatial.org/files/?artifact_id=47664 )
+ *
+ * @author Xavier Sumba ([email protected]))
+ */
+public class EhInsideFunction implements NativeFunction {
+
+    // auto-register for SPARQL environment
+    static {
+        if 
(!FunctionRegistry.getInstance().has(FN_GEOSPARQL.EH_INSIDE.toString())) {
+            FunctionRegistry.getInstance().add(new EhInsideFunction());
+        }
+    }
+
+    @Override
+    public Value evaluate(ValueFactory valueFactory, Value... args) throws 
ValueExprEvaluationException {
+        throw new UnsupportedOperationException("cannot evaluate in-memory, 
needs to be supported by the database");
+    }
+
+    @Override
+    public String getURI() {
+        return FN_GEOSPARQL.EH_INSIDE.toString();
+    }
+
+    /**
+     * Return true if this function has available native support for the given
+     * dialect
+     *
+     * @param dialect
+     * @return
+     */
+    @Override
+    public boolean isSupported(KiWiDialect dialect) {
+        return dialect instanceof PostgreSQLDialect;
+    }
+
+    /**
+     * Return a string representing how this GeoSPARQL function is translated
+     * into SQL ( Postgis Function ) in the given dialect
+     *
+     * @param dialect
+     * @param args
+     * @return
+     */
+    @Override
+    public String getNative(KiWiDialect dialect, String... args) {
+        if (dialect instanceof PostgreSQLDialect) {
+            if (args.length == 2) {
+                String geom1 = args[0];
+                String geom2 = args[1];
+                String SRID_default = "4326";
+                /*
+                 * The following condition is required to read WKT  inserted 
directly into args[0] or args[1] and create a geometries with SRID
+                 * POINT, MULTIPOINT, LINESTRING ... and MULTIPOLYGON 
conditions: 
+                 *   example: geof:ehInside(?geom, "POLYGON(( -7 43, -2 43, -2 
38, -7 38, -7 43))"^^geo:wktLiteral)
+                 * st_AsText condition: It is to use the geometry that is the 
result of another function geosparql.
+                 *   example: geof:ehInside(?geom, geof:buffer(?geom2, 50, 
units:meter))
+                 */
+                if (args[0].contains("POINT") || 
args[0].contains("MULTIPOINT") || args[0].contains("LINESTRING") || 
args[0].contains("MULTILINESTRING") || args[0].contains("POLYGON") || 
args[0].contains("MULTIPOLYGON") || args[0].contains("ST_AsText")) {
+                    geom1 = String.format("ST_GeomFromText(%s,%s)", args[0], 
SRID_default);
+                }
+                if (args[1].contains("POINT") || 
args[1].contains("MULTIPOINT") || args[1].contains("LINESTRING") || 
args[1].contains("MULTILINESTRING") || args[1].contains("POLYGON") || 
args[1].contains("MULTIPOLYGON") || args[1].contains("ST_AsText")) {
+                    geom2 = String.format("ST_GeomFromText(%s,%s)", args[1], 
SRID_default);
+                }
+                return String.format("ST_Relate(%s, %s, 'TFF*FFT**')", geom1, 
geom2);
+            }
+        }
+        throw new UnsupportedOperationException("ehInside function not 
supported by dialect " + dialect);
+    }
+
+    /**
+     * Get the return type of the function. This is needed for SQL type casting
+     * inside KiWi.
+     *
+     * @return
+     */
+    @Override
+    public ValueType getReturnType() {
+        return ValueType.BOOL;
+    }
+
+    /**
+     * Get the argument type of the function for the arg'th argument (starting
+     * to count at 0). This is needed for SQL type casting inside KiWi.
+     *
+     * @param arg
+     * @return
+     */
+    @Override
+    public ValueType getArgumentType(int arg) {
+        return ValueType.GEOMETRY;
+    }
+
+    /**
+     * Return the minimum number of arguments this function requires.
+     *
+     * @return
+     */
+    @Override
+    public int getMinArgs() {
+        return 2;
+    }
+
+    /**
+     * Return the maximum number of arguments this function can take
+     *
+     * @return
+     */
+    @Override
+    public int getMaxArgs() {
+        return 2;
+    }
+}

http://git-wip-us.apache.org/repos/asf/marmotta/blob/df172223/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhMeetFunction.java
----------------------------------------------------------------------
diff --git 
a/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhMeetFunction.java
 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhMeetFunction.java
new file mode 100644
index 0000000..e340048
--- /dev/null
+++ 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhMeetFunction.java
@@ -0,0 +1,152 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.marmotta.kiwi.sparql.geosparql.functions;
+
+import org.apache.marmotta.kiwi.persistence.KiWiDialect;
+import org.apache.marmotta.kiwi.persistence.pgsql.PostgreSQLDialect;
+import org.apache.marmotta.kiwi.sparql.builder.ValueType;
+import org.apache.marmotta.kiwi.sparql.function.NativeFunction;
+import org.apache.marmotta.kiwi.vocabulary.FN_GEOSPARQL;
+import org.openrdf.model.Value;
+import org.openrdf.model.ValueFactory;
+import org.openrdf.query.algebra.evaluation.ValueExprEvaluationException;
+import org.openrdf.query.algebra.evaluation.function.FunctionRegistry;
+
+/**
+ * A SPARQL function for analyze the Meet Relate between two geometries. Should
+ * be implemented directly in the database, as the in-memory implementation is
+ * non-functional. Only support by postgres - POSTGIS
+ * <p/>
+ * The function can be called either as:
+ * <ul>
+ *      <li>geof:ehMeet(?geometryA, ?geometryB) </li>
+ * </ul>
+ * Meet Relate is calculated with "DE-9IM Intersection Pattern": defined in
+ * "RCC8 Query Functions Table 6" from "DE-9IM Intersection Pattern" from OGC
+ * GEOSPARQL DOCUMENT (
+ * https://portal.opengeospatial.org/files/?artifact_id=47664 )
+ *
+ * @author Xavier Sumba ([email protected]))
+ */
+public class EhMeetFunction implements NativeFunction {
+
+    // auto-register for SPARQL environment
+    static {
+        if 
(!FunctionRegistry.getInstance().has(FN_GEOSPARQL.EH_MEET.toString())) {
+            FunctionRegistry.getInstance().add(new EhMeetFunction());
+        }
+    }
+
+    @Override
+    public Value evaluate(ValueFactory valueFactory, Value... args) throws 
ValueExprEvaluationException {
+        throw new UnsupportedOperationException("cannot evaluate in-memory, 
needs to be supported by the database");
+    }
+
+    @Override
+    public String getURI() {
+        return FN_GEOSPARQL.EH_MEET.toString();
+    }
+
+    /**
+     * Return true if this function has available native support for the given
+     * dialect
+     *
+     * @param dialect
+     * @return
+     */
+    @Override
+    public boolean isSupported(KiWiDialect dialect) {
+        return dialect instanceof PostgreSQLDialect;
+    }
+
+    /**
+     * Return a string representing how this GeoSPARQL function is translated
+     * into SQL ( Postgis Function ) in the given dialect
+     *
+     * @param dialect
+     * @param args
+     * @return
+     */
+    @Override
+    public String getNative(KiWiDialect dialect, String... args) {
+      if (dialect instanceof PostgreSQLDialect) {
+            if (args.length == 2) {
+                String geom1 = args[0];
+                String geom2 = args[1];
+                String SRID_default = "4326";
+                /*
+                 * The following condition is required to read WKT  inserted 
directly into args[0] or args[1] and create a geometries with SRID
+                 * POINT, MULTIPOINT, LINESTRING ... and MULTIPOLYGON 
conditions: 
+                 *   example: geof:ehMeet(?geom1, "POLYGON(( -7 43, -2 43, -2 
38, -7 38, -7 43))"^^geo:wktLiteral)
+                 * st_AsText condition: It is to use the geometry that is the 
result of another function geosparql.
+                 *   example: geof:ehMeet(?geom1, geof:buffer(?geom2, 50, 
units:meter))
+                 */
+                if (args[0].contains("POINT") || 
args[0].contains("MULTIPOINT") || args[0].contains("LINESTRING") || 
args[0].contains("MULTILINESTRING") || args[0].contains("POLYGON") || 
args[0].contains("MULTIPOLYGON") || args[0].contains("ST_AsText")) {
+                    geom1 = String.format("ST_GeomFromText(%s,%s)", args[0], 
SRID_default);
+                }
+                if (args[1].contains("POINT") || 
args[1].contains("MULTIPOINT") || args[1].contains("LINESTRING") || 
args[1].contains("MULTILINESTRING") || args[1].contains("POLYGON") || 
args[1].contains("MULTIPOLYGON") || args[1].contains("ST_AsText")) {
+                    geom2 = String.format("ST_GeomFromText(%s,%s)", args[1], 
SRID_default);
+                }
+                return String.format("ST_Relate(%s, %s, 'F***T****')", geom1, 
geom2);
+            }
+        }
+        throw new UnsupportedOperationException("ehMeet function not supported 
by dialect " + dialect);
+    }
+
+    /**
+     * Get the return type of the function. This is needed for SQL type casting
+     * inside KiWi.
+     *
+     * @return
+     */
+    @Override
+    public ValueType getReturnType() {
+        return ValueType.BOOL;
+    }
+
+    /**
+     * Get the argument type of the function for the arg'th argument (starting
+     * to count at 0). This is needed for SQL type casting inside KiWi.
+     *
+     * @param arg
+     * @return
+     */
+    @Override
+    public ValueType getArgumentType(int arg) {
+        return ValueType.GEOMETRY;
+    }
+
+    /**
+     * Return the minimum number of arguments this function requires.
+     *
+     * @return
+     */
+    @Override
+    public int getMinArgs() {
+        return 2;
+    }
+
+    /**
+     * Return the maximum number of arguments this function can take
+     *
+     * @return
+     */
+    @Override
+    public int getMaxArgs() {
+        return 2;
+    }
+}

http://git-wip-us.apache.org/repos/asf/marmotta/blob/df172223/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhOverlapFunction.java
----------------------------------------------------------------------
diff --git 
a/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhOverlapFunction.java
 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhOverlapFunction.java
new file mode 100644
index 0000000..605e304
--- /dev/null
+++ 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EhOverlapFunction.java
@@ -0,0 +1,153 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.marmotta.kiwi.sparql.geosparql.functions;
+
+import org.apache.marmotta.kiwi.persistence.KiWiDialect;
+import org.apache.marmotta.kiwi.persistence.pgsql.PostgreSQLDialect;
+import org.apache.marmotta.kiwi.sparql.builder.ValueType;
+import org.apache.marmotta.kiwi.sparql.function.NativeFunction;
+import org.apache.marmotta.kiwi.vocabulary.FN_GEOSPARQL;
+import org.openrdf.model.Value;
+import org.openrdf.model.ValueFactory;
+import org.openrdf.query.algebra.evaluation.ValueExprEvaluationException;
+import org.openrdf.query.algebra.evaluation.function.FunctionRegistry;
+
+/**
+ * A SPARQL function for analyze the Overlap Relate between two geometries.
+ * Should be implemented directly in the database, as the in-memory
+ * implementation is non-functional. Only support by postgres - POSTGIS
+ * <p/>
+ * The function can be called either as:
+ * <ul>
+ *      <li>geof:ehOverlap(?geometryA, ?geometryB) </li>
+ * </ul>
+ * Overlap Relate is calculated with "DE-9IM Intersection Pattern": defined in
+ * "RCC8 Query Functions Table 6" from "DE-9IM Intersection Pattern" from OGC
+ * GEOSPARQL DOCUMENT (
+ * https://portal.opengeospatial.org/files/?artifact_id=47664 )
+ *
+ * @author Xavier Sumba ([email protected]))
+ */
+public class EhOverlapFunction implements NativeFunction {
+
+    // auto-register for SPARQL environment
+    static {
+        if 
(!FunctionRegistry.getInstance().has(FN_GEOSPARQL.EH_OVERLAP.toString())) {
+            FunctionRegistry.getInstance().add(new EhOverlapFunction());
+        }
+    }
+
+    @Override
+    public Value evaluate(ValueFactory valueFactory, Value... args) throws 
ValueExprEvaluationException {
+        throw new UnsupportedOperationException("cannot evaluate in-memory, 
needs to be supported by the database");
+    }
+
+    @Override
+    public String getURI() {
+        return FN_GEOSPARQL.EH_OVERLAP.toString();
+    }
+
+    /**
+     * Return true if this function has available native support for the given
+     * dialect
+     *
+     * @param dialect
+     * @return
+     */
+    @Override
+    public boolean isSupported(KiWiDialect dialect) {
+        return dialect instanceof PostgreSQLDialect;
+    }
+
+    /**
+     * Return a string representing how this GeoSPARQL function is translated
+     * into SQL ( Postgis Function ) in the given dialect
+     *
+     * @param dialect
+     * @param args
+     * @return
+     */
+    @Override
+    public String getNative(KiWiDialect dialect, String... args) {
+
+        if (dialect instanceof PostgreSQLDialect) {
+            if (args.length == 2) {
+                String geom1 = args[0];
+                String geom2 = args[1];
+                String SRID_default = "4326";
+                /*
+                 * The following condition is required to read WKT  inserted 
directly into args[0] or args[1] and create a geometries with SRID
+                 * POINT, MULTIPOINT, LINESTRING ... and MULTIPOLYGON 
conditions: 
+                 *   example: geof:ehOverlap(?geom, "POLYGON(( -7 43, -2 43, 
-2 38, -7 38, -7 43))"^^geo:wktLiteral)
+                 * st_AsText condition: It is to use the geometry that is the 
result of another function geosparql.
+                 *   example: geof:ehOverlap(?geom, geof:buffer(?geom2, 50, 
units:meter))
+                 */
+                if (args[0].contains("POINT") || 
args[0].contains("MULTIPOINT") || args[0].contains("LINESTRING") || 
args[0].contains("MULTILINESTRING") || args[0].contains("POLYGON") || 
args[0].contains("MULTIPOLYGON") || args[0].contains("ST_AsText")) {
+                    geom1 = String.format("ST_GeomFromText(%s,%s)", args[0], 
SRID_default);
+                }
+                if (args[1].contains("POINT") || 
args[1].contains("MULTIPOINT") || args[1].contains("LINESTRING") || 
args[1].contains("MULTILINESTRING") || args[1].contains("POLYGON") || 
args[1].contains("MULTIPOLYGON") || args[1].contains("ST_AsText")) {
+                    geom2 = String.format("ST_GeomFromText(%s,%s)", args[1], 
SRID_default);
+                }
+                return String.format("ST_Relate(%s, %s, 'T*T***T**')", geom1, 
geom2);
+            }
+        }
+        throw new UnsupportedOperationException("ehOverlap function not 
supported by dialect " + dialect);
+    }
+
+    /**
+     * Get the return type of the function. This is needed for SQL type casting
+     * inside KiWi.
+     *
+     * @return
+     */
+    @Override
+    public ValueType getReturnType() {
+        return ValueType.BOOL;
+    }
+
+    /**
+     * Get the argument type of the function for the arg'th argument (starting
+     * to count at 0). This is needed for SQL type casting inside KiWi.
+     *
+     * @param arg
+     * @return
+     */
+    @Override
+    public ValueType getArgumentType(int arg) {
+        return ValueType.GEOMETRY;
+    }
+
+    /**
+     * Return the minimum number of arguments this function requires.
+     *
+     * @return
+     */
+    @Override
+    public int getMinArgs() {
+        return 2;
+    }
+
+    /**
+     * Return the maximum number of arguments this function can take
+     *
+     * @return
+     */
+    @Override
+    public int getMaxArgs() {
+        return 2;
+    }
+}

http://git-wip-us.apache.org/repos/asf/marmotta/blob/df172223/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EnvelopeFunction.java
----------------------------------------------------------------------
diff --git 
a/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EnvelopeFunction.java
 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EnvelopeFunction.java
new file mode 100644
index 0000000..378dca9
--- /dev/null
+++ 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/EnvelopeFunction.java
@@ -0,0 +1,148 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.marmotta.kiwi.sparql.geosparql.functions;
+
+import org.apache.marmotta.kiwi.persistence.KiWiDialect;
+import org.apache.marmotta.kiwi.persistence.pgsql.PostgreSQLDialect;
+import org.apache.marmotta.kiwi.sparql.builder.ValueType;
+import org.apache.marmotta.kiwi.sparql.function.NativeFunction;
+import org.apache.marmotta.kiwi.vocabulary.FN_GEOSPARQL;
+import org.openrdf.model.Value;
+import org.openrdf.model.ValueFactory;
+import org.openrdf.query.algebra.evaluation.ValueExprEvaluationException;
+import org.openrdf.query.algebra.evaluation.function.FunctionRegistry;
+
+/**
+ * A SPARQL function for doing an envelope of a geometry. Should be implemented
+ * directly in the database, as the in-memory implementation is non-functional.
+ * Only support by postgres - POSTGIS
+ * <p/>
+ * The function can be called either as:
+ * <ul>
+ *      <li>geof:envelope(?geometryA) </li>
+ * </ul>
+ * Its necesary enable postgis in your database with the next command "CREATE
+ * EXTENSION postgis;" Note that for performance reasons it might be 
preferrable
+ * to create a geometry index for your database. Please consult your database
+ * documentation on how to do this.
+ *
+ * @author Xavier Sumba ([email protected]))
+ */
+public class EnvelopeFunction implements NativeFunction {
+
+    // auto-register for SPARQL environment
+    static {
+        if 
(!FunctionRegistry.getInstance().has(FN_GEOSPARQL.ENVELOPE.toString())) {
+            FunctionRegistry.getInstance().add(new EnvelopeFunction());
+        }
+    }
+
+    @Override
+    public Value evaluate(ValueFactory valueFactory, Value... args) throws 
ValueExprEvaluationException {
+        throw new UnsupportedOperationException("cannot evaluate in-memory, 
needs to be supported by the database");
+    }
+
+    @Override
+    public String getURI() {
+        return FN_GEOSPARQL.ENVELOPE.toString();
+    }
+
+    /**
+     * Return true if this function has available native support for the given
+     * dialect
+     *
+     * @param dialect
+     * @return
+     */
+    @Override
+    public boolean isSupported(KiWiDialect dialect) {
+        return dialect instanceof PostgreSQLDialect;
+    }
+
+    /**
+     * Return a string representing how this GeoSPARQL function is translated
+     * into SQL ( Postgis Function ) in the given dialect
+     *
+     * @param dialect
+     * @param args
+     * @return
+     */
+    @Override
+    public String getNative(KiWiDialect dialect, String... args) {
+        if (dialect instanceof PostgreSQLDialect) {
+            if (args.length == 1) {
+                String geom1 = args[0];
+                String SRID_default = "4326";
+                /*
+                 * The following conditions is required to read WKT  inserted 
directly into args[0] and create a geometries with SRID
+                 * POINT, MULTIPOINT, LINESTRING ... and MULTIPOLYGON 
conditions: 
+                 *   example: geof:envelope("POLYGON(( -7 43, -2 43, -2 38, -7 
38, -7 43))"^^geo:wktLiteral)
+                 * st_AsText condition: It is to use the geometry that is the 
result of another function geosparql.
+                 *   example: geof:envelope(geof:buffer(?geom, 50, 
units:meter))
+                 */
+                if (args[0].contains("POINT") || 
args[0].contains("MULTIPOINT") || args[0].contains("LINESTRING") || 
args[0].contains("MULTILINESTRING") || args[0].contains("POLYGON") || 
args[0].contains("MULTIPOLYGON") || args[0].contains("ST_AsText")) {
+                    geom1 = String.format("ST_GeomFromText(%s,%s)", args[0], 
SRID_default);
+                }
+                return String.format("ST_AsText(ST_Envelope(%s)) ", geom1);
+            }
+        }
+        throw new UnsupportedOperationException("Envelope function not 
supported by dialect " + dialect);
+    }
+
+    /**
+     * Get the return type of the function. This is needed for SQL type casting
+     * inside KiWi.
+     *
+     * @return
+     */
+    @Override
+    public ValueType getReturnType() {
+        return ValueType.GEOMETRY;
+    }
+
+    /**
+     * Get the argument type of the function for the arg'th argument (starting
+     * to count at 0). This is needed for SQL type casting inside KiWi.
+     *
+     * @param arg
+     * @return
+     */
+    @Override
+    public ValueType getArgumentType(int arg) {
+        return ValueType.GEOMETRY;
+    }
+
+    /**
+     * Return the minimum number of arguments this function requires.
+     *
+     * @return
+     */
+    @Override
+    public int getMinArgs() {
+        return 1;
+    }
+
+    /**
+     * Return the maximum number of arguments this function can take
+     *
+     * @return
+     */
+    @Override
+    public int getMaxArgs() {
+        return 1;
+    }
+}

http://git-wip-us.apache.org/repos/asf/marmotta/blob/df172223/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/GetSRIDFunction.java
----------------------------------------------------------------------
diff --git 
a/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/GetSRIDFunction.java
 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/GetSRIDFunction.java
new file mode 100644
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b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/GetSRIDFunction.java
@@ -0,0 +1,136 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.marmotta.kiwi.sparql.geosparql.functions;
+
+import org.apache.marmotta.kiwi.persistence.KiWiDialect;
+import org.apache.marmotta.kiwi.persistence.pgsql.PostgreSQLDialect;
+import org.apache.marmotta.kiwi.sparql.builder.ValueType;
+import org.apache.marmotta.kiwi.sparql.function.NativeFunction;
+import org.apache.marmotta.kiwi.vocabulary.FN_GEOSPARQL;
+import org.openrdf.model.Value;
+import org.openrdf.model.ValueFactory;
+import org.openrdf.query.algebra.evaluation.ValueExprEvaluationException;
+import org.openrdf.query.algebra.evaluation.function.FunctionRegistry;
+
+/**
+ * Returns the spatial reference system URI for geom.. Should be implemented
+ * directly in the database, as the in-memory implementation is non-functional.
+ * Only support by postgres - POSTGIS
+ * <p/>
+ * The function can be called either as:
+ * <ul>
+ * <li>geof:getSRID(?geometryA) </li>
+ * </ul>
+ * Its necesary enable postgis in your database with the next command "CREATE
+ * EXTENSION postgis;" Note that for performance reasons it might be 
preferrable
+ * to create a geometry index for your database. Please consult your database
+ * documentation on how to do this.
+ *
+ * @author Xavier Sumba ([email protected]))
+ */
+public class GetSRIDFunction implements NativeFunction {
+
+    // auto-register for SPARQL environment
+    static {
+        if 
(!FunctionRegistry.getInstance().has(FN_GEOSPARQL.GETSRID.toString())) {
+            FunctionRegistry.getInstance().add(new GetSRIDFunction());
+        }
+    }
+
+    @Override
+    public Value evaluate(ValueFactory valueFactory, Value... args) throws 
ValueExprEvaluationException {
+        throw new UnsupportedOperationException("cannot evaluate in-memory, 
needs to be supported by the database");
+    }
+
+    @Override
+    public String getURI() {
+        return FN_GEOSPARQL.GETSRID.toString();
+    }
+
+    /**
+     * Return true if this function has available native support for the given
+     * dialect
+     *
+     * @param dialect
+     * @return
+     */
+    @Override
+    public boolean isSupported(KiWiDialect dialect) {
+        return dialect instanceof PostgreSQLDialect;
+    }
+
+    /**
+     * Return a string representing how this GeoSPARQL function is translated
+     * into SQL ( Postgis Function ) in the given dialect
+     *
+     * @param dialect
+     * @param args
+     * @return
+     */
+    @Override
+    public String getNative(KiWiDialect dialect, String... args) {
+        if (dialect instanceof PostgreSQLDialect) {
+            if (args.length == 1) {
+                return String.format("ST_SRID(%s)", args[0]);
+            }
+        }
+        throw new UnsupportedOperationException("getSRID function not 
supported by dialect " + dialect);
+    }
+
+    /**
+     * Get the return type of the function. This is needed for SQL type casting
+     * inside KiWi.
+     *
+     * @return
+     */
+    @Override
+    public ValueType getReturnType() {
+        return ValueType.INT;
+    }
+
+    /**
+     * Get the argument type of the function for the arg'th argument (starting
+     * to count at 0). This is needed for SQL type casting inside KiWi.
+     *
+     * @param arg
+     * @return
+     */
+    @Override
+    public ValueType getArgumentType(int arg) {
+        return ValueType.GEOMETRY;
+    }
+
+    /**
+     * Return the minimum number of arguments this function requires.
+     *
+     * @return
+     */
+    @Override
+    public int getMinArgs() {
+        return 1;
+    }
+
+    /**
+     * Return the maximum number of arguments this function can take
+     *
+     * @return
+     */
+    @Override
+    public int getMaxArgs() {
+        return 1;
+    }
+}

http://git-wip-us.apache.org/repos/asf/marmotta/blob/df172223/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/IntersectionFunction.java
----------------------------------------------------------------------
diff --git 
a/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/IntersectionFunction.java
 
b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/IntersectionFunction.java
new file mode 100644
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b/libraries/kiwi/kiwi-geosparql/src/main/java/org/apache/marmotta/kiwi/sparql/geosparql/functions/IntersectionFunction.java
@@ -0,0 +1,152 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.marmotta.kiwi.sparql.geosparql.functions;
+
+import org.apache.marmotta.kiwi.persistence.KiWiDialect;
+import org.apache.marmotta.kiwi.persistence.pgsql.PostgreSQLDialect;
+import org.apache.marmotta.kiwi.sparql.builder.ValueType;
+import org.apache.marmotta.kiwi.sparql.function.NativeFunction;
+import org.apache.marmotta.kiwi.vocabulary.FN_GEOSPARQL;
+import org.openrdf.model.Value;
+import org.openrdf.model.ValueFactory;
+import org.openrdf.query.algebra.evaluation.ValueExprEvaluationException;
+import org.openrdf.query.algebra.evaluation.function.FunctionRegistry;
+
+/**
+ * A SPARQL function for doing a intersection between two geometries. Should be
+ * implemented directly in the database, as the in-memory implementation is
+ * non-functional. Only support by postgres - POSTGIS
+ * <p/>
+ * The function can be called either as:
+ * <ul>
+ *      <li>geof:intersection(?geometryA, ?geometryB) </li>
+ * </ul>
+ * Its necesary enable postgis in your database with the next command "CREATE
+ * EXTENSION postgis;" Note that for performance reasons it might be 
preferrable
+ * to create a geometry index for your database. Please consult your database
+ * documentation on how to do this.
+ *
+ * @author Xavier Sumba ([email protected]))
+ */
+public class IntersectionFunction implements NativeFunction {
+
+    // auto-register for SPARQL environment
+    static {
+        if 
(!FunctionRegistry.getInstance().has(FN_GEOSPARQL.INTERSECTION.toString())) {
+            FunctionRegistry.getInstance().add(new IntersectionFunction());
+        }
+    }
+
+    @Override
+    public Value evaluate(ValueFactory valueFactory, Value... args) throws 
ValueExprEvaluationException {
+        throw new UnsupportedOperationException("cannot evaluate in-memory, 
needs to be supported by the database");
+    }
+
+    @Override
+    public String getURI() {
+        return FN_GEOSPARQL.INTERSECTION.toString();
+    }
+
+    /**
+     * Return true if this function has available native support for the given
+     * dialect
+     *
+     * @param dialect
+     * @return
+     */
+    @Override
+    public boolean isSupported(KiWiDialect dialect) {
+        return dialect instanceof PostgreSQLDialect;
+    }
+
+    /**
+     * Return a string representing how this GeoSPARQL function is translated
+     * into SQL ( Postgis Function ) in the given dialect
+     *
+     * @param dialect
+     * @param args
+     * @return
+     */
+    @Override
+    public String getNative(KiWiDialect dialect, String... args) {
+        if (dialect instanceof PostgreSQLDialect) {
+            if (args.length == 2) {
+                String geom1 = args[0];
+                String geom2 = args[1];
+                String SRID_default = "4326";
+                /*
+                 * The following condition is required to read WKT  inserted 
directly into args[0] or args[1] and create a geometries with SRID
+                 * POINT, MULTIPOINT, LINESTRING ... and MULTIPOLYGON 
conditions: 
+                 *   example: geof:intersection(?geom1, "POLYGON(( -7 43, -2 
43, -2 38, -7 38, -7 43))"^^geo:wktLiteral)
+                 * st_AsText condition: It is to use the geometry that is the 
result of another function geosparql.
+                 *   example: geof:intersection(?geom1, geof:buffer(?geom2, 
50, units:meter))
+                 */
+                if (args[0].contains("POINT") || 
args[0].contains("MULTIPOINT") || args[0].contains("LINESTRING") || 
args[0].contains("MULTILINESTRING") || args[0].contains("POLYGON") || 
args[0].contains("MULTIPOLYGON") || args[0].contains("ST_AsText")) {
+                    geom1 = String.format("ST_GeomFromText(%s,%s)", args[0], 
SRID_default);
+                }
+                if (args[1].contains("POINT") || 
args[1].contains("MULTIPOINT") || args[1].contains("LINESTRING") || 
args[1].contains("MULTILINESTRING") || args[1].contains("POLYGON") || 
args[1].contains("MULTIPOLYGON") || args[1].contains("ST_AsText")) {
+                    geom2 = String.format("ST_GeomFromText(%s,%s)", args[1], 
SRID_default);
+                }
+                return String.format("ST_AsText(st_Intersection(%s , %s ) )", 
geom1, geom2);
+            }
+        }
+        throw new UnsupportedOperationException("Intersection function not 
supported by dialect " + dialect);
+    }
+
+    /**
+     * Get the return type of the function. This is needed for SQL type casting
+     * inside KiWi.
+     *
+     * @return
+     */
+    @Override
+    public ValueType getReturnType() {
+        return ValueType.GEOMETRY;
+    }
+
+    /**
+     * Get the argument type of the function for the arg'th argument (starting
+     * to count at 0). This is needed for SQL type casting inside KiWi.
+     *
+     * @param arg
+     * @return
+     */
+    @Override
+    public ValueType getArgumentType(int arg) {
+        return ValueType.GEOMETRY;
+    }
+
+    /**
+     * Return the minimum number of arguments this function requires.
+     *
+     * @return
+     */
+    @Override
+    public int getMinArgs() {
+        return 2;
+    }
+
+    /**
+     * Return the maximum number of arguments this function can take
+     *
+     * @return
+     */
+    @Override
+    public int getMaxArgs() {
+        return 2;
+    }
+}

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